Question

HTML forms & java script problem

Asked by: gallacter

Hi I'm new to java and I'm trying to create a simple calculator for addition and subtraction of two numbers.  Could anybody please help me where I'm going wrong as I can't seem to add or subtract at al?


<title>hello</title>

<script type="text/javascript">
<!--
function showAnswer()
      {
            document.AnswerMe.myOutput1.value = eval(document.AnswerMe.myInput.Value + document.AnswerMe.myInput2.Value)
      }
function showAnswer2(
      {
            document.AnswerMe.myOutput2.value = eva(document.AnswerMe.myInput.Value - document.AnswerMe.myInput2.Value)


//-->
</script>


<pre><h1>Calculator</h1></pre>


<form name="AnswerMe">
Enter first number <input type="text" size="10" value="1" name="myInput">
Enter second number <input type="text" size="10" value="2"name="myInput2">
<input type="button" value="+ " onclick="showAnswer(document.AnswerMe.myInput.value)">
<input type="button" value=" - " onclick="showAnswer2(document.AnswerMe.myInput2.value)">

Thrice your number is <input type="text" size="10" value="Answer goes here" name="myOutput1">
Thrice your number is <input type="text" size="10" value="Answer goes here" name="myOutput2">

</form>

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Asked On
2004-02-16 at 12:29:20ID20886859
Topic

Hypertext Markup Language (HTML)

Participating Experts
3
Points
125
Comments
3

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Answers

 

by: webwomanPosted on 2004-02-16 at 12:40:10ID: 10375587

Try
<input type="button" value="+ " onclick="showAnswer()">
<input type="button" value=" - " onclick="showAnswer2()">

And also, try this...
document.AnswerMe.myOutput1.value = eval(document.AnswerMe.myInput.Value) + eval(document.AnswerMe.myInput2.Value)

Othewise you're probably adding two strings and then taking the value -- 2+3=23

 

by: peter58Posted on 2004-02-16 at 13:03:49ID: 10375786

Try this code below, I tried it and it seemed to work fine, just for your interest the .value bit should be a lower case v.

<title>hello</title>

<script type="text/javascript">
<!--
function showAnswer(FormField)
     {
          document.AnswerMe.myOutput1.value = eval(document.AnswerMe.myInput.value) + eval(document.AnswerMe.myInput2.value);
     }
function showAnswer2()
     {
          document.AnswerMe.myOutput2.value = eval(document.AnswerMe.myInput.value) - eval(document.AnswerMe.myInput2.value)
       }

//-->
</script>


<pre><h1>Calculator</h1></pre>


<form name="AnswerMe">
Enter first number <input type="text" size="10" value="1" name="myInput">
Enter second number <input type="text" size="10" value="2" name="myInput2">
<input type="button" value="+" onclick="showAnswer(myInput)">
<input type="button" value="-" onclick="showAnswer2(myInput2)">

Thrice your number is <input type="text" size="10" value="Answer goes here" name="myOutput1">
Thrice your number is <input type="text" size="10" value="Answer goes here" name="myOutput2">
</form>

 

by: shofstetterPosted on 2004-02-25 at 09:49:07ID: 10452443

Here is a simple javascript calculator that I wrote a while ago.  Usual with javascript the problem with adding is the way js handles it's variables.  if js thinks it's a string it will just concat the two values instead of just adding them. so when you assign values to your variables from a text box you have to use eval so that it forces js to look at them as numbers:)



<HTML>
<HEAD>
<style type="text/css">
input{
WIDTH: 100%;
HEIGHT: 100%;
}
td{
width:25%;
height:20%;
VERTICAL-ALIGN: middle;
TEXT-ALIGN: center;
}
</style>
<BODY bgcolor=silver>
<table align="center" border=1 width="200" height="250">
<tr><td colspan=4>
<input name="data" id="data"
      style="FONT-WEIGHT: bold; FONT-SIZE: large; FONT-FAMILY: sans-serif; BACKGROUND-COLOR: limegreen;
     TEXT-ALIGN: right"
     >
</td></tr>
<tr><td>
<input type="button" value="CE" onclick="init_calc()" size=24>
</td><td>
<input type="button" value="+" onclick="add_click()" id=button1 name=button1>
</td><td>
<input type="button" value="-" onclick="subtract_click()" id=button2 name=button2>
</td><td>
<input type="button" value="*" onclick="multiply_click()" id=button2 name=button2>
</td></tr>
<tr><td>
<input type="button" value="1" onclick="numclick(1)" id=button4 name=button4>
</td><td>
<input type="button" value="2" onclick="numclick(2)" id=button5 name=button5>
</td><td>
<input type="button" value="3" onclick="numclick(3)" id=button6 name=button6>
</td><td>
<input type="button" value="/" onclick="divide_click()" id=button2 name=button2>
</td></tr>
<tr><td>
<input type="button" value="4" onclick="numclick(4)" id=button8 name=button8>
</td><td>
<input type="button" value="5" onclick="numclick(5)" id=button9 name=button9>
</td><td>
<input type="button" value="6" onclick="numclick(6)" id=button10 name=button10>
</td><td>
<INPUT id=button2 onclick="equal_click()" type=button value== name='button2"'>
</td></tr>
<tr><td>
<input type="button" value="7" onclick="numclick(7)" id=button12 name=button12>
</td><td>
<input type="button" value="8" onclick="numclick(8)" id=button13 name=button13>
</td><td>
<input type="button" value="9" onclick="numclick(9)" id=button14 name=button14>
</td><td>
<input type="button" value="0" onclick="numclick(0)" id=button2 name=button2>
</td></tr></table>
</BODY>
</HTML>


<script language="javascript">
var num1 = 0;
var num2 = 0;
var flag = 0;
var numflg = 0;

function init_calc()
{
num1 = 0;
num2 = 0;
flag = 0;
numflg = 0;
data.value = "";
}
function numclick(num)
{
data.value = data.value + num;
}

function add_click()
{
num1 = eval(data.value);
data.value = "";
flag = 1;
}

function subtract_click()
{
num1 = eval(data.value);
data.value = "";
flag = 2;
}

function multiply_click()
{
num1 = eval(data.value);
data.value = "";
flag = 3;
}
function divide_click()
{
num1 = eval(data.value);
data.value = "";
flag = 4;
}

function equal_click()
{
num2 = eval(data.value);
data.value = "";
switch(flag){
case 1:data.value = ((num1) + (num2));
break;
case 2:data.value = ((num1) - (num2));
break;
case 3:data.value = ((num1) * (num2));
break;
case 4:data.value = ((num1) / (num2));
break;
}
flag = 0;
num1 = 0;
num2 = 0;
}
</script>

20120131-EE-VQP-002

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